Review of Prof. Johnson’s Report on American Coals. 333 
The following classified view of twenty five varieties of coal 
has been derived from the table of ranks above mentioned, and 
may serve to indicate the practical value for steam navigation of 
the several classes. 
ta Hires ~ 7 
se | | S3lau [s2- Eee 
Ow 1O.8 a|ses je" e-tegs 
ee as B= 23 |Ses fees 
rs) os © rs) Nace = Ss 8 3 
Class of Names of samples. S33 | “s/e8 Is 2° [28 8 
coals. S2aziags Ep lS. ea Sicee 
S5S/3F3| So is ss/Fee sess 
SSS/SSS| SS \Sa5/S se RISES 
See) ae ee 2 
Cumber- |Atkinson & Templeman’s, - - | 1000} 1000| 282 | 828] 505 | 3615 
land, (Md.)|Easby’s coal in store, - - 936 | 946| 451 | 658} 286 
Free burn-'Easby & Smith’s, a ee Se 931] 903} 197 | 886] 329 } 3246 
ing, bitu--New York and Md. Mining Co.’s, 914| 927) 111 | 677| 376 | 3005 
minous. eff’, - - - - = = | 882] 906) 133/ 877] 298 
erages, - - + - | 932] 936| 235 | 785! 359 13248 
Vv 
Beaver Meadow, slope 5, —- - 923. 982) 1000; 72 
Anthra- | Forest Improvement, (Schuylkill,) 940} 955} 741} 790} 150 [3576 
cites of |Peach Mountain, (Schuylkill,)  - 5| 964} 1 143 
Pennsyl- |Lackawa 15| 844; 484) 779| 187 {3209 
Vania. Lehigh, NS an aes - | 835) 872} 555) 792) 153 43207 
Averages, -  - ~ = | 911] 923 797 
Free burn-(Quin’s Run, - - - -  - {| 960| 913| 458) 726; 667 43724 
ing bitu- |Blossburg, -  - - = = | 908) 911} 176) 996 3586 
minous |Dauphin and Susquehanna, - - | 873| 835) 171| 766) 602 | 3287 
coals of /Cambria County, - - ~- - | 863] 860} 172| 867) 250 | 3012 
Pennsyl- {Lycoming Creek, -  - + = - 871} 184] 706) 291 42885 
vani . “687 | 878! 232{ 892! 481 13299 
(Chesterfield Mining Company, - | 841) 726) 143/1000) 427 13137 
Highly bi-\Midlothian, screened, - - - | 836| 722| 180| 730| 388 | 2856 
tuminous |Creek Company’s, - + = | 787| 692) 136; 981 9 
Crouch & Snead's ole eh TON 7864. LIS) 6 1 | 2743 
Virginia, |Tippecanoe,- - - ~- - | 724| 618) 149) 875 376 | 2742 
Averages, - i 793 | '709| 144] 844| 384 2872 
gees castle, Eng. > es = | BON] 776, 191, B27, 595 | 3198 
Foreign _|Pictou, (Cunart’s sample,) N. S., 792 | 738 | 928; 588 | 3143 
bitumin- Sidney, . . bes a iy PSG ka pes plo bo sor} S167 
° wir Se, er ee, eee : 
sail iSoucke "By * 2:2 2} 649} 625] 107} 947] 521 | 2749 
Averages, - - - - 746 | 694| 197! 844| 526 13027 
tees BE ce iin Sie SOA: eee SS BS Uae as 
ral_|Maryland free burning coals, = {1000} 1000; 395} 880 2 
977 | 986 | 1000} 893} 319 
938 | 390} 1000; 914 
ues for jnous, - 951 
rom the {Virginia bituminous, - - ? 850 | 757 ” sag ie 
averages of/Foreign bituminous, - - - 801) 741 
each class. 
From the above scale it appears that in evaporative power under 
equal weights, the Cumberland class surpasses the anthracites by 
‘about 2-3 per cent., and under equal bulks, by 1-4 percent. They 
also surpass the foreign bituminous coals 20 per cent. when we 
compare equal weights, and 26 per cent. by equal bulks. In 
freedom from clinker the anthracites stand preéminent ; in rapid 
production of steam, when once in action, the Pennsylvania bitu- 
Vol. xx1x, No. 2.—July-Sept. 1845. 43 
